Administration of abciximab to patients receiving tirofiban or eptifibatide: Effect on platelet function

OBJECTIVES The goal of this study was to evaluate platelet function and to preliminarily assess the clinical safety of sequential treatment with tirof iban or eptifibatide followed by abciximab in patients undergoing percutane ous coronary intervention (PCI). BACKGROUND An increasing number of acute coronary syndrome (ACS) patients a re treated early with tirofiban or eptifibatide. Some later require PCI and may benefit from switching to abciximab, for which long-term benefits have been reported. METHODS Fifty ACS patients planned for PCI were enrolled. Twenty five patie nts received tirofiban followed by abciximab. Ten patients received eptifib atide followed by abciximab. Fifteen patients received only abciximab. All patients had blood samples drawn six times during the therapeutic course. P latelet function was evaluated by ADP- and TRAP-induced aggregation, flow c ytometry analysis of fibrinogen binding and the cone and plate(let) analyze r, which tests shear rate-dependent platelet activation. RESULTS Administered after tirofiban, abciximab caused a significant furthe r decline in platelet function, as evidenced by all methods. Administered a fter eptifibatide, abciximab caused a significant further reduction in plat elet function, as assessed by the cone and plate(let) analyzer and fibrinog en binding methods. The platelet inhibition achieved by the combination the rapy was always greater than or equal to that achieved by abciximab alone. There were no major bleeding or severe thrombocytopenia episodes. Three of the 35 combination therapy patients and one of the 15 who received abcixima b alone had minor bleeding. CONCLUSIONS This is the first in vivo study of combination intravenous plat elet glycoprotein IIb/IIIa inhibitor therapy. Administration of abciximab i mmediately after tirofiban or eptifibatide therapy effectively inhibits pla telet function and appears to be safe. (J Am Coil Cardiol 2001; 37:847-55) (C) 2001 by the American College of Cardiology.